Berlin 2024 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 3: Ultrafast Magnetization Effects I

MA 3.4: Vortrag

Montag, 18. März 2024, 10:30–10:45, H 2013

Sub-wavelength localised all-optical helicity-independent switching in GdTbCo using plasmonic gold nanodisks — Themistoklis Sidiropoulos, •Puloma Singh, Tino Noll, Michael Schneider, Dieter Engel, Felix Steinbach, Ingo Will, Denny Sommer, Clemens von Korff Schmising, and Stefan Eisebitt — Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Berlin, Germany

All-optical helicity-independent switching (AO-HIS) is of interest for ultrafast and energy efficient magnetic switching in future magnetic data storage approaches. Yet, to achieve high bit density magnetic recording it is necessary to reduce the size of magnetic bits while controlling their shape and position. Metallic nanostructures that support localized surface plasmons enable electromagnetic confinement well below the diffraction limit and rare-earth transition metal alloys such as GdTbCo have demonstrated nanometer-sized stable domains. Here, we deposit plasmonic gold nanodisks on GdTbCo films and probe the magnetic state using magnetic force microscopy. We observe localised AO-HIS of the sample after resonant excitation of the gold nanodisks by a single 370 fs long laser pulse with a center wavelength of 1030 nm. We demonstrate that the strong localization of optical fields through plasmonic nanodisks enables nanoscale AOS-HIS at a sub-wavelength scale length which is comparable to structure sizes in commercial heat assisted magnetic recording. Moreover, we study the influence of the localized electromagnetic field enhancement by the plasmonic nanoparticles on the required fluence to switch the magnetization.

Keywords: Plasmonics; All optical Switching; Ultrafast magnetization dynamics; Nanoscale